Methods and tools have been developed to search and exploit potential reservoirs of hydrocarbons in subterranean environments (e.g., subsurface and/or subsea). In some cases, measurements of formation porosity and density are used to identify potential oil and gas reserves as well as to estimate the volume of the reserve.
Nuclear logging tools are sometimes used to measure the interactions between radiation emitted from such a tool and the formation, as well as naturally occurring radiation. Tools including gamma ray detectors are sometimes employed to measure formation porosity and lithology.
A gamma ray detector mounted in a housing is typically inserted through an opening in a tool housing and mounted internal to the tool housing. A separate cover is attached to the housing to cover the opening and protect the detector in the separate housing. The additional material of the cover between the detector housing and the formation shades the detector from receipt of the formation gamma rays and may degrade its performance.